1. Field of the Invention
The present invention relates to a thermosensitive recording method and thermosensitive recording apparatus and in particular, to a thermosenstivie recording method and thermosensitive recording apparatus in which a recording condition is changed according to a temperature of a recording device.
2. Description of the Related Art
Conventionally, this type of photosensitive recording method and apparatus have been used for reducing a recording time while maintaining a sufficient print concentration such as a character and a symbol on a recording paper. Moreover, a technique utilizing a recording device temperature is disclosed, for example, in Japanese Patent Publication (unexamined) A-5-268436 and A-3-297687, in which a recording device temperature is automatically supplied to a register so that the register can be read when required, thus enabling to reduce the CPU load. Japanese Patent Publication (unexamined) A-62-193851, in which thermosensitive recording apparatus having sift resistor to control ON/OFF of drive device. Object of this related art is reduction of energy consumption.
FIG. 4 is a block diagram showing this conventional photosensitive recording apparatus that comprises: a recording device 42 for printing on a recording paper with a print energy generated when a voltage is applied; a temperature sensor 43 for detecting a temperature of the recording device 42; a cutter for cutting the recording paper; a drive block 44 for feeding the recording paper; a position sensor for detecting a leading edge of the recording paper; and a recording controller 41 which operates as follows. That is, upon reception of a record start command, the record controller 41 checks the temperature shown by the temperature sensor 43.
If the check result is equal to or above a predetermined temperature (for example, 25 degrees C.), the record controller 42 sets a predetermined normal speed (for example V=13 mm/sec) as the recording paper feed speed during a recording operation for printing on the recording paper, and a predetermined normal print energy as the print energy of the recording device 42. For example, the normal print energy is such that when a printing is performed at the normal recording paper feed speed with the recording device 42 at a temperature of 25 degrees C., or above, it is possible to obtain a sufficient print concentration as a black ratio representing a ratio of a print area occupied by black.
Moreover, if the aforementioned check result is below 25 degrees C., in order to obtain a predetermined black ratio or above, the recording paper feed speed is set lower than the normal speed during a recording operation and the print energy of the recording device 42 is set to the normal print energy; or the recording paper feed speed is maintained at the normal speed and the print energy of the recording device 42 is set higher than the normal print energy.
Next, explanation will be given on the operation of the conventional photosensitive recording apparatus.
The record controller 41, upon reception of a record start command, checks the temperature indicated by the temperature sensor 43 and stores the temperature value. Next, the record controller 41 performs a roll-back operation. That is, the recording paper which has been waiting with its leading edge at a wait position 47 is rolled back to a record start position 48 by a drive block 44.
If the check result stored is equal to or above 25 degrees C., the record controller 41 causes the drive block 44 to feed the recording paper at a normal speed and supplies to a recording device 42 a printing pulse indicating a printing period (print energy generation period) from a print start to a print end. The printing device 42 is made to print on the printing paper with a normal print energy. In this case, the printing state is equal to or above a predetermined black ratio and brings about a sufficient print concentration.
Moreover, if the check result stored is below 25 degrees C., in order to obtain a print state of sufficient print concentration equal to or above the predetermined black ratio, the drive block 44 is operated so as to feed the recording paper at a lower speed than the normal speed while the recording device 42 prints on the printing paper with the normal print energy, or the drive block 44 is operated so as to feed the recording paper at the normal speed while the print pulse is supplied to the recording device 42 so as to print on the recording paper with a higher print energy than the normal print energy.
In the aforementioned thermosensitive recording apparatus, when the recording device temperature is below 25 degrees C., in order to obtain a print state equal to or above a predetermined black ratio, there is a necessity to slow down the print speed (recording paper feed speed) or increase the recording device print energy.